I'm no expert, but have you tried Loctite? :smoke:
Rocker Arm constantly coming loose
I have a 69 Cougar with a 351W and for the past week I've had a rocker arm on the drivers side head come loose. I've tightened it down 6-8 times since last week and did it again about 2 hours ago only to have it come loose shortly after. I heard that the nuts on the rocker arms wear out and should be replaced. Is this true? I bought a nut for the one rocker arm but like usual one of them came loose. I don't know if it is the same one or not and wont know until tomorrow because I'm done working on it today. I need some opinions on what I could do to keep them tight so I don't have to listen to that ticking sound anymore. Any info would be appreciated.
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No I haven't. I probably wont unless that is my last resort. Thanks for the quick reply.I'm no expert, but have you tried Loctite? :smoke:
-Justin
+1 I had to on my re manufactured engine from pepboys. Did it and haven't had a problem since. Also make sure the studs aren't pulling out either, had that happen to the same engine.I'm no expert, but have you tried Loctite? :smoke:
-Andy
Haven't checked the studs. I didn't even think of that. Thanks for the reply. I'll check the stud tomorrow. Loctite sounds like it may be the way to go.+1 I had to on my re manufactured engine from pepboys. Did it and haven't had a problem since. Also make sure the studs aren't pulling out either, had that happen to the same engine.
-Andy
-Justin
You said that you "Have tightened it down 6-8 times since" How are you tightening them down?I have a 69 Cougar with a 351W and for the past week I've had a rocker arm on the drivers side head come loose. I've tightened it down 6-8 times since last week and did it again about 2 hours ago only to have it come loose shortly after. I heard that the nuts on the rocker arms wear out and should be replaced. Is this true? I bought a nut for the one rocker arm but like usual one of them came loose. I don't know if it is the same one or not and wont know until tomorrow because I'm done working on it today. I need some opinions on what I could do to keep them tight so I don't have to listen to that ticking sound anymore. Any info would be appreciated.
Sounds like the stud is gradually pulling out. My brother had that happen on an F150 and it drove him crazy trying to figure it out. After you adjust the nut, count the number of visible threads and then count them again after it comes "loose" If there is no change in the number of visible threads, then you know the stud is pulling out.
Unless the head (or stud) has been replaced, the 69 has positive stop rocker studs, meaning there is no adjustment so the nut is tightened down against a shoulder on the stud.
Replace the locknut with another (5/16x24 IIRC). If that doesn't work put another nut on top as a jamnut.
Replace the locknut with another (5/16x24 IIRC). If that doesn't work put another nut on top as a jamnut.
Wow. Thanks for all the replies. When I first tightened the nut my dad said to loosen the nut until you heard it clicking then to tighten it down until the sound stops. If I tighten the nut too much it sounds like the engine is going to stall so I back the nut off a little bit and it will be fine until I drive it around for 5-10 minutes then it would be loose again. I haven't checked the stud but I will today possibly within the next few hours. The heads are completely stock and nothing has been replaced. Thanks for the help.
-Justin
-Justin
Correct for adjustable valvetrains, incorrect for non-adjustable valvetrains.When I first tightened the nut my dad said to loosen the nut until you heard it clicking then to tighten it down until the sound stops.
This is normal and is due to bleed-down of the lifters. When adjusting adjustable valvetrain with the engine running, one has to adjust slowly to allow the lifter to bleed down. If you do it too fast, the valve does not shut all the way (until the lifter bleeds down).If I tighten the nut too much it sounds like the engine is going to stall...
If the valvetrain is non-adjustable (and I'll bet it is), this would be normal. The only way the nuts are locked is when they are torqued against the shoulder on the studs. Read on and I'll explain....so I back the nut off a little bit and it will be fine until I drive it around for 5-10 minutes then it would be loose again.
The procedure you outline above is for ADJUSTABLE valvetrains ONLY. As Art pointed out, you should have non-adjustable valvetrain (unless the heads are from another year or have been changed to adjustable).
Here's something to check in order to tell:
Non-Adjustable: 5/16" fine threads with a shoulder where the studs become 3/8" diameter (non-threaded), this is the diameter that presses into the head.
Adjustable: 3/8" fine threads that end with no shoulder to the 3/8" shank of the stud which presses into the head.
If you have the 5/16" nuts and you are adjusting them as if they are adjustable, what you are experiencing is to be expected.
The proper way to adjust NA valvetrain is to tighten down to the shoulder and torque against the shoulder. This is done with the engine not running and the whole shebang depends on the machine shop having set the valve stem tip heights correctly (hopefully they have).
In any case, sounds like you have NA valve train and need to torque them, not adjust them.
Hope this helps,
Bob
My buddy told me the same thing! Damn if the rocker arms were loose in a miute or so. So I opted to tighten down per spec and no more loose rocker arms
I just finished doing it again. I noticed that when the nut came loose the rocker arm wasn't centered on the stud so the nut wasn't seated correctly in the rocker arm. So with the engine off I centered the rocker arm on the stud (haven't done this previously) and held it in place while putting the nut on so the nut would set correctly in the rocker arm. Then I tightened the nut until I couldn't tighten it anymore which I assume is correct since I don't have an adjustable valvetrain. I drove it for around 10 minutes and everything seems fine so far. You guys are helping me out a lot. Thanks.
-Justin
-Justin
My daily driver 1970 351W was doing the same thing on two rockers. I bought new nuts and after installing them, I could watch the nuts start backing off again until the cylinder was dead. The motor was owned by callous hands before me so I figured the nasty, dirty black oil in it when I got it was holding things together. So I put a second nut on it and 10 thousand miles later...still holding and running smooth.
Thanks for the reply. I too had the dirty nasty oil so I wiped out the stud and the center of the rocker arm before installing the new nuts. Everything seems fine now. I replaced all the nuts but one since Riebes only had 15 nuts. Anyways I think my main problem was I didn't know what I was doing but thanks to you guys I learned some new things. I finished yesterday but haven't really driven it around but I'm sure it won't come loose again.My daily driver 1970 351W was doing the same thing on two rockers. I bought new nuts and after installing them, I could watch the nuts start backing off again until the cylinder was dead. The motor was owned by callous hands before me so I figured the nasty, dirty black oil in it when I got it was holding things together. So I put a second nut on it and 10 thousand miles later...still holding and running smooth.
-Justin
couldnt he run a poly lock like the roller rockers come with?
Haven't actually checked, but I've never seen them in the 5/16" size that would be required. Only 3/8" and 7/16".couldnt he run a poly lock like the roller rockers come with?
I'm having the same problem with rocker nuts coming loose. I have a 1969 Cougar XR7 with a 351W engine. The heads are stock, and original with 5/16-24 studs, and stock rockers/pushrods/lifters. The responses above seem like they will be very helpful, but I have a couple of questions for clarity.
1. "Art" above suggested: "Replace the locknut with another (5/16x24 IIRC)". I'm not sure whether that means to replace with another new locknut, or switch from a lock nut to a different kind of nut. My initial thought was to use a locknuts like the distorted style shown at this link: https://www.amazon.com/Thread-Stover-Locknut-Medium-Carbon/dp/B00Z3X3T0C?th=1 However, in those nuts the threads go all of the way to the bottom of the nut. The other option was a non-locking flange head nut similar to this link: The Official ARP Web Site | Kits These flanged nuts have a thread that stops inside just above the flange; and seem very similar to the stock nuts on the rockers. Which ones would be recommended?
2. According to "Art", "the 69 has positive stop rocker studs, meaning there is no adjustment so the nut is tightened down against a shoulder on the stud. " Does this mean that regardless of the engine rotation (which cylinder is opening/closing, firing order, etc.) .... so, all I have to do is torque all of the rocker nuts down to 17-23 ft lbs?
3. If 2 is true, then it would seem that the type of nut answered in question 1 would be more important. The first "distorted thread lock nuts" may have a torque reading that was slightly off, and the base of the nut would be slightly higher once torqued down since there is no flange. The second "flanged non-locking nuts" would apply slightly higher preload because of flanged surface being slightly lower than the bottom of the threads inside the nut.
1. "Art" above suggested: "Replace the locknut with another (5/16x24 IIRC)". I'm not sure whether that means to replace with another new locknut, or switch from a lock nut to a different kind of nut. My initial thought was to use a locknuts like the distorted style shown at this link: https://www.amazon.com/Thread-Stover-Locknut-Medium-Carbon/dp/B00Z3X3T0C?th=1 However, in those nuts the threads go all of the way to the bottom of the nut. The other option was a non-locking flange head nut similar to this link: The Official ARP Web Site | Kits These flanged nuts have a thread that stops inside just above the flange; and seem very similar to the stock nuts on the rockers. Which ones would be recommended?
2. According to "Art", "the 69 has positive stop rocker studs, meaning there is no adjustment so the nut is tightened down against a shoulder on the stud. " Does this mean that regardless of the engine rotation (which cylinder is opening/closing, firing order, etc.) .... so, all I have to do is torque all of the rocker nuts down to 17-23 ft lbs?
3. If 2 is true, then it would seem that the type of nut answered in question 1 would be more important. The first "distorted thread lock nuts" may have a torque reading that was slightly off, and the base of the nut would be slightly higher once torqued down since there is no flange. The second "flanged non-locking nuts" would apply slightly higher preload because of flanged surface being slightly lower than the bottom of the threads inside the nut.
I've not seen the non-adjustable 1969 style, but one would think that if it is non-adjustable, you would hit a flange of some sort with the nut and it would then get a nice torque to hold it. Yes, if it is non-adjustable you can install the rockers and tighten them down in any order anytime regardless of what the crank is doing. You may not even need locking nuts, since they are snug against a shoulder of some sort like any other nut, but I may be wrong there- some nuts like torque converter nuts are locking. If it's a deformed thread locking style (or any style), that will affect the torque needed to get it tight against the shoulder.
If it's the adjustable style then you have to do the routine of rotating the engine to certain spots and tightening until the pushrod gets snug and then add a partial turn. That style definitely needs locknuts since you don't really tighten them against a solid item.
I hope that I didn't confuse you more. Pictures may help.
If it's the adjustable style then you have to do the routine of rotating the engine to certain spots and tightening until the pushrod gets snug and then add a partial turn. That style definitely needs locknuts since you don't really tighten them against a solid item.
I hope that I didn't confuse you more. Pictures may help.
351 Windsors were never made with an adjustable valvetrain. The 69-77 engines had self-guided rail rocker arms with torque down bottleneck studs. Bolt down sled fulcrum style rocker arms were introduced in 1978. The nuts are a displaced thread self locking type, so run them down to the shoulder and torque to spec. It doesn't matter where you are on the firing order.
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